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Debt Obligations (Details) $ in Thousands |  |  |  | 1 Months Ended | 12 Months Ended |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | ---
Aug. 22, 2018 USD ($) NotesSeries | Aug. 04, 2017 USD ($) item | Jul. 16, 2014 USD ($) | Jan. 31, 2018 engine | Dec. 31, 2018 USD ($) | Dec. 31, 2016 USD ($) | Dec. 31, 2017 USD ($) | Jun. 30, 2016 USD ($) item | Apr. 30, 2016 USD ($)
Long Term Debt |  |  |  |  |  |  |  |  |
Maturity term |  | 10 years |  |  |  |  |  |  |
Percentage of the funding for the purchase of a corporate aircraft |  |  |  |  | 100.00% |  |  |  |
Principal outstanding repayable |  |  |  |  |  |  |  |  |
2019 |  |  |  |  | $ 55,380 |  |  |  |
2020 |  |  |  |  | 54,980 |  |  |  |
2021 |  |  |  |  | 482,217 |  |  |  |
2022 |  |  |  |  | 207,733 |  |  |  |
2023 |  |  |  |  | 34,008 |  |  |  |
Thereafter |  |  |  |  | 524,112 |  |  |  |
Total |  |  |  |  | 1,358,430 |  | $ 1,103,743 |  |
Less: unamortized debt issuance costs |  |  |  |  | (21,081) |  | (18,338) |  |
Total debt obligations |  |  |  |  | $ 1,337,349 |  | $ 1,085,405 |  |
Gains (Losses) on Extinguishment of Debt |  |  |  |  |  | $ (137) |  |  |
One-month LIBOR |  |  |  |  |  |  |  |  |
Long Term Debt |  |  |  |  |  |  |  |  |
One-month LIBOR rate (as a percent) |  |  |  |  | 2.50% |  | 1.57% |  |
WEST III |  |  |  |  |  |  |  |  |
Long Term Debt |  |  |  |  |  |  |  |  |
Number of series notes | item |  | 2 |  |  |  |  |  |  |
Credit facility at a floating rate of interest of one-month LIBOR plus 2.0% and maturity date of April 2021 |  |  |  |  |  |  |  |  |
Long Term Debt |  |  |  |  |  |  |  |  |
Maximum borrowing capacity under credit facility |  |  |  |  | $ 890,000 |  |  |  |
Fixed rate (as a percent) |  |  |  |  | 2.00% |  |  |  |
Principal outstanding repayable |  |  |  |  |  |  |  |  |
Total |  |  |  |  | $ 427,000 |  | $ 491,000 |  |
WEST IV |  |  |  |  |  |  |  |  |
Long Term Debt |  |  |  |  |  |  |  |  |
Number of series notes | NotesSeries | 2 |  |  |  |  |  |  |  |
Aggregate principal amount | $ 373,400 |  |  |  |  |  |  |  |
Line of credit facility outstanding amount |  |  |  |  | $ 369,200 |  |  |  |
WEST IV Series A 2018 term notes payable at a fixed rate of interest of 4.75%, maturing in September 2043, secured by engines |  |  |  |  |  |  |  |  |
Long Term Debt |  |  |  |  |  |  |  |  |
Fixed rate (as a percent) |  |  |  |  | 4.75% |  |  |  |
Notes issues at price of par (as percentage) | 99.99853% |  |  |  |  |  |  |  |
Aggregate principal amount | $ 326,800 |  |  |  |  |  |  |  |
Maturity term | 8 years |  |  |  |  |  |  |  |
Principal outstanding repayable |  |  |  |  |  |  |  |  |
Total |  |  |  |  | $ 323,075 |  |  |  |
WEST IV Series B 2018 term notes payable at a fixed rate of interest of 5.44%, maturing in September 2043, secured by engines |  |  |  |  |  |  |  |  |
Long Term Debt |  |  |  |  |  |  |  |  |
Fixed rate (as a percent) |  |  |  |  | 5.44% |  |  |  |
Notes issues at price of par (as percentage) | 99.99504% |  |  |  |  |  |  |  |
Aggregate principal amount | $ 46,700 |  |  |  |  |  |  |  |
Maturity term | 8 years |  |  |  |  |  |  |  |
Principal outstanding repayable |  |  |  |  |  |  |  |  |
Total |  |  |  |  | $ 46,154 |  |  |  |
WEST III |  |  |  |  |  |  |  |  |
Long Term Debt |  |  |  |  |  |  |  |  |
Line of credit facility outstanding amount |  |  |  |  | $ 313,400 |  | 330,700 |  |
WEST III Series A 2017 term notes payable at a fixed rate of interest of 4.69%, maturing in August 2042, secured by engines |  |  |  |  |  |  |  |  |
Long Term Debt |  |  |  |  |  |  |  |  |
Fixed rate (as a percent) |  |  |  |  | 4.69% |  |  |  |
Principal outstanding repayable |  |  |  |  |  |  |  |  |
Total |  |  |  |  | $ 274,205 |  | 289,295 |  |
WEST III Series A 2017 term notes payable at a fixed rate of interest of 4.69%, maturing in August 2042, secured by engines | WEST III |  |  |  |  |  |  |  |  |
Long Term Debt |  |  |  |  |  |  |  |  |
Fixed rate (as a percent) |  |  |  |  | 4.69% |  |  |  |
Aggregate principal amount |  | $ 293,700 |  |  |  |  |  |  |
WEST III Series B 2017 term notes payable at a fixed rate of interest of 6.36%, maturing in August 2042, secured by engines |  |  |  |  |  |  |  |  |
Long Term Debt |  |  |  |  |  |  |  |  |
Fixed rate (as a percent) |  |  |  |  | 6.36% |  |  |  |
Principal outstanding repayable |  |  |  |  |  |  |  |  |
Total |  |  |  |  | $ 39,212 |  | 41,370 |  |
WEST III Series B 2017 term notes payable at a fixed rate of interest of 6.36%, maturing in August 2042, secured by engines | WEST III |  |  |  |  |  |  |  |  |
Long Term Debt |  |  |  |  |  |  |  |  |
Fixed rate (as a percent) |  |  |  |  | 6.36% |  |  |  |
Aggregate principal amount |  | $ 42,000 |  |  |  |  |  |  |
WEST II Series A 2012 term notes payable at a fixed rate of interest of 5.50%, maturing in September 2037, secured by engines |  |  |  |  |  |  |  |  |
Long Term Debt |  |  |  |  |  |  |  |  |
Fixed rate (as a percent) |  |  |  |  | 5.50% |  |  |  |
Line of credit facility outstanding amount |  |  |  |  | $ 173,800 |  |  |  |
Principal outstanding repayable |  |  |  |  |  |  |  |  |
Total |  |  |  |  | $ 237,847 |  | 259,022 |  |
Note payable at fixed interest rates ranging from 2.60% to 2.97%, maturing in July 2024, secured by an aircraft |  |  |  |  |  |  |  |  |
Long Term Debt |  |  |  |  |  |  |  |  |
Number of series notes | item |  |  |  |  |  |  |  | 2 |
Aggregate principal amount |  |  | $ 13,400 |  |  |  |  | $ 4,700 |
Maturity term |  |  | 10 years |  |  |  |  |  |
Initial term for interest payment |  |  |  |  | 5 years |  |  |  |
Principal outstanding repayable |  |  |  |  |  |  |  |  |
Total |  |  |  |  | $ 10,937 |  | 12,720 |  |
Note payable at fixed interest rates ranging from 2.60% to 2.97%, maturing in July 2024, secured by an aircraft | Minimum |  |  |  |  |  |  |  |  |
Long Term Debt |  |  |  |  |  |  |  |  |
Fixed rate (as a percent) |  |  |  |  | 2.60% |  |  |  |
Note payable at fixed interest rates ranging from 2.60% to 2.97%, maturing in July 2024, secured by an aircraft | Maximum |  |  |  |  |  |  |  |  |
Long Term Debt |  |  |  |  |  |  |  |  |
Fixed rate (as a percent) |  |  |  |  | 2.97% |  |  |  |
Note payable at a variable interest rate of one-month LIBOR plus 2.25%, matured in January 2018, secured by engines |  |  |  |  |  |  |  |  |
Long Term Debt |  |  |  |  |  |  |  |  |
Fixed rate (as a percent) |  |  |  |  | 2.25% |  |  |  |
Principal outstanding repayable |  |  |  |  |  |  |  |  |
Total |  |  |  |  |  |  | 10,336 |  |
Number of engines pledged as collateral | engine |  |  |  | 3 |  |  |  |  |
Revolving credit facility |  |  |  |  |  |  |  |  |
Long Term Debt |  |  |  |  |  |  |  |  |
Maximum borrowing capacity under credit facility |  |  |  |  |  |  |  |  | $ 890,000
Amount of debt available under accordion feature |  |  |  |  |  |  |  |  | 1,000,000
Line of credit facility outstanding amount |  |  |  |  | $ 427,000 |  |  |  |
Principal outstanding repayable |  |  |  |  |  |  |  |  |
Remaining borrowing capacity available |  |  |  |  | $ 463,000 |  | $ 399,000 |  |
Maximum borrowing capacity under credit facility before amendment |  |  |  |  |  |  |  |  | $ 700,000

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- Definition Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-04.(a)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24072-122690 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6802200&loc=d3e1835-112601 + Details
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